I own a hasselblad h3d-39 and fuji gx680, so I was really excited when kapture group just recently released their new H adapter for fuji that allowed infinity focus. Also hasselblad backs do not need the one shot box, so that was a big plus too. Adapter is great, but any shutter speed past 1/125th or 1/60th has horrible color castes and artifacts. Interestingly though this is only with ambient light, in studio even at 1/400th it sync perfectly. I have tried different lenses but it did not make a difference. Right now I am using a generic sync cable to sync the back and the fuji together, after reading online I found that there is some special cables from hasselblad for the fuji, but there are several, and I am not exactly sure which one would be the right one, or if I even need one. So if anyone else has experience using h3d backs on the fuji, I would love to here it. Also here are the link to the cables I am talking about.

I have an ixpress to fuji 680 adapter somewhere in my gear closet, and my recollection is it came with several cables, one for each model of the 680 - each model requiring a specific cable. Tomorrow I'll pull the box and have a look for you just in case this will help. Which model camera do you have?

Another thing to check, maybe you already did, is the settings on the back / or in phocus. You need to have the setting in software slower than whatever your shutter speed is otherwise it can get funky.

The Fuji GX680 flash sync signal is always a 1/15th sec pulse whatever the camera is set to.Digital backs use the duration of the flash sync to tell the back what the shutter speed is.So unfortunately with the gx680 the back thinks it's doing a 1/15th o a second exposure.

This is why kapture group came up with the One Shot box. This box wakes up the back and also sends a sync duration that corresponds to the shutter speed set on the cameraand one shot box.

Some backs can work by staying awake, but they will still receive the 1/15 sec sync pulse.

I'm not sure how this is going to affect your back, but I'm guessing exposures longer that 1/15th will be under exposed.For shorter exposures the back will be exposing for 1/15th even if your shutter opens for 1/400th.This will affect noise and may explain the artifacts you are getting.

The Fuji GX680 flash sync signal is always a 1/15th sec pulse whatever the camera is set to.Digital backs use the duration of the flash sync to tell the back what the shutter speed is.So unfortunately with the gx680 the back thinks it's doing a 1/15th o a second exposure.

This is why kapture group came up with the One Shot box. This box wakes up the back and also sends a sync duration that corresponds to the shutter speed set on the cameraand one shot box.

Some backs can work by staying awake, but they will still receive the 1/15 sec sync pulse.

I'm not sure how this is going to affect your back, but I'm guessing exposures longer that 1/15th will be under exposed.For shorter exposures the back will be exposing for 1/15th even if your shutter opens for 1/400th.This will affect noise and may explain the artifacts you are getting.

Thanks for the info. I had gone through this before using a leaf back and my main reason for going the hasselblad route was I supposedly did not need a one shot box for all hasselblad backs, looks like I might still need one.

I have an ixpress to fuji 680 adapter somewhere in my gear closet, and my recollection is it came with several cables, one for each model of the 680 - each model requiring a specific cable. Tomorrow I'll pull the box and have a look for you just in case this will help. Which model camera do you have?

Another thing to check, maybe you already did, is the settings on the back / or in phocus. You need to have the setting in software slower than whatever your shutter speed is otherwise it can get funky.

Thanks for the info, this is somewhat worrying that each model of the gx680 needs a different cable. I am using the fuji gx680 III with my h3d-39 and the 2nd gen kapture group H adapters that allow infinity focus. As far as the setting on the back/phocus the only setting that comes close to working is setting it to flashsync mode, and for shutter speed, the fastest I can set it on the back is 1/8th. I tried lower speeds like 1/4th or even 1 sec, but never made a difference. I'll try contacting hasselblad about it. Thanks again for your info!

Thanks for the info, this is somewhat worrying that each model of the gx680 needs a different cable. I am using the fuji gx680 III with my h3d-39 and the 2nd gen kapture group H adapters that allow infinity focus. As far as the setting on the back/phocus the only setting that comes close to working is setting it to flashsync mode, and for shutter speed, the fastest I can set it on the back is 1/8th. I tried lower speeds like 1/4th or even 1 sec, but never made a difference. I'll try contacting hasselblad about it. Thanks again for your info!

Each model of Fuji gx680 should not require different cables. I have made several and they all work on the three generations of the camera.

Between the Fuji GX680 models nothing has changed with the multi function connector on the side.For example the Kapture Group control box is compatible with all three generation of the Fuji GX680.The only changes are in protocol on the contacts on the back of the camera that are only used by Fuji backs (film and digital).Despite the change Fuji came up with film backs that supported both all 5 Fuji gx680 models. They are the 680IIIn backs.

The only digital back adapter that uses the contacts on the back of the camera is the adapter made by Sinar.

Thanks for the info. I had gone through this before using a leaf back and my main reason for going the hasselblad route was I supposedly did not need a one shot box for all hasselblad backs, looks like I might still need one.

For the best results at all shutter speeds you need a One Shot box.

The way the one shot box works is this.

The one shot has a release button on it and you have to use it to shoot. It also has a cable release you can plug into it.So the camera is fired by the control box. The control box gets a 1/15th of a second closed circuit over the flash sync from the camera.The instant this starts the back receives a closed circuit, but it is from the one shot box and is of the duration of the selected expose time on the camera and box. (the two have to match).The box also sends a wake up signal to the back the same time it sends the shuter release to the camera. As the mirror goes up the backwakes up. This gives you the best quality the back can produce and better battery life as well as less heat in the sensor.

Kapture group just does things the best way with the One Shot 680 control box.

I contacted kapture group and they assured me a one-shot box was un-needed with the h3d-39, somehow I think they might be wrong on this one since I am not having much luck. Going to try the cable solution first, worst case scenario I will pick up a one shot box.

You mentioned that you have made several cables, can you give any more info that?

The cables I made were for remote mirror up. Double release button. First pressure raises the mirror, second fires the flash.

There is also a way to get a different flash sync pulse from the lens rather than the body. I have seen lenses modified with a sync socket on the lens.Getting the sync pulse from the lens gives the back a signal that corresponds to the exact durration of the shutter.

I do not have the schematics of this lense sync modification, but if I find it I'll post it here.

The cables I made were for remote mirror up. Double release button. First pressure raises the mirror, second fires the flash.

There is also a way to get a different flash sync pulse from the lens rather than the body. I have seen lenses modified with a sync socket on the lens.Getting the sync pulse from the lens gives the back a signal that corresponds to the exact durration of the shutter.

I do not have the schematics of this lense sync modification, but if I find it I'll post it here.

The one shot has a release button on it and you have to use it to shoot. It also has a cable release you can plug into it.So the camera is fired by the control box. The control box gets a 1/15th of a second closed circuit over the flash sync from the camera.The instant this starts the back receives a closed circuit, but it is from the one shot box and is of the duration of the selected expose time on the camera and box. (the two have to match).The box also sends a wake up signal to the back the same time it sends the shuter release to the camera. As the mirror goes up the backwakes up. This gives you the best quality the back can produce and better battery life as well as less heat in the sensor.

Kapture group just does things the best way with the One Shot 680 control box.

Hi FredBGG ,I have a Mamiya DM22 digital back which is the another name of the Leaf Aptus II5. I also have the Fujifilm GX680III. I already bought an adapter plate to mount the back to the camera. Do I also need a KG OneShot box cable to sync the two? Many Thanks.

Hi FredBGG ,I have a Mamiya DM22 digital back which is the another name of the Leaf Aptus II5. I also have the Fujifilm GX680III. I already bought an adapter plate to mount the back to the camera. Do I also need a KG OneShot box cable to sync the two? Many Thanks.

Hi SimonJ -

While Fred is not present on the forum, there are many others here who can answer questions like these. And by posting it in the forum instead of a PM, other members can also benefit from the information.

Unfortunately the answer is yes, Leaf backs require a KG One Shot Box also. There is no other practical method for either Phase One or Leaf digital backs to interface with a Fuji GX680, that I am aware of. Neither company ever produced their own Fuji interface (as Imacon/Hasselblad - and Sinar - did/do).

While Fred is not present on the forum, there are many others here who can answer questions like these. And by posting it in the forum instead of a PM, other members can also benefit from the information.

Unfortunately the answer is yes, Leaf backs require a KG One Shot Box also. There is no other practical method for either Phase One or Leaf digital backs to interface with a Fuji GX680, that I am aware of. Neither company ever produced their own Fuji interface (as Imacon/Hasselblad - and Sinar - did/do).